Runabout 5.0

The Runabout is an extension of the Java libraries that adds two-argument multi-dispatch to Java without changing the language or the VM.
It uses reflection to find visit methods, which are invoked using dynamically generated and loaded code. The Runabout does not need a special compiler or changes to Javas syntax.
Dispatch with the Runabout is fairly fast, typically a factor of two to ten times slower than double dispatch. The Runabout is useful since it can help to make code faster and more readable. For example, a sequence of instanceof tests is a clear sign that a Runabout should be used instead.
Enhancements:
- This release makes the Runabout code much simpler.
- The goal was to make it easier for users to understand code using the Runabout by avoiding feature-bloat.
- The major changes are elimination of features.
- Specifically, there is no longer support for primitive types or user-defined dispatching functions.
- Supporting primitive types would interact badly with the auto (un)boxing features that are new in Java 5.0.
- The implementation was cleaned up to make use of the new features of Java 5.0.
- As a result, the new version works only with Java 5.0 or higher.